Shippagan
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Shippagan clear sky chart from 2005-11-05 to 2017-03-14.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.
Observation TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(no limit)Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
28%
14207
12%
45154
5%
14167
35%
14167
15%
33032

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
14%
750
8%
2685
1%
746
22%
746
8%
2121
January16th to endNight
20%
781
15%
2667
4%
781
34%
781
13%
1897
February1st to 15thNight
25%
704
11%
2286
3%
701
35%
701
16%
1621
February16th to endNight
26%
631
11%
2051
4%
631
35%
631
12%
1529
March1st to 15thNight
25%
715
17%
1998
7%
715
34%
715
17%
1461
March16th to endNight
25%
704
16%
1936
5%
704
34%
704
19%
1378
April1st to 15thNight
30%
503
15%
1608
9%
503
36%
503
17%
1143
April16th to endNight
32%
495
16%
1485
10%
495
38%
495
21%
1025
May1st to 15thNight
35%
495
11%
1361
7%
495
40%
495
20%
992
May16th to endNight
34%
472
9%
1327
4%
471
38%
471
19%
976
June1st to 15thNight
36%
330
6%
1155
4%
330
38%
330
13%
844
June16th to endNight
38%
330
4%
1155
3%
330
39%
330
14%
848
July1st to 15thNight
52%
310
10%
1085
10%
310
55%
310
22%
697
July16th to endNight
44%
419
7%
1208
5%
391
45%
391
18%
862
August1st to 15thNight
48%
494
9%
1466
8%
490
50%
490
21%
1028
August16th to endNight
48%
525
13%
1593
9%
525
52%
525
24%
1061
September1st to 15thNight
37%
495
15%
1650
9%
495
45%
495
22%
1077
September16th to endNight
38%
657
20%
1840
11%
657
45%
657
30%
1157
October1st to 15thNight
31%
660
17%
1980
8%
660
40%
660
22%
1348
October16th to endNight
21%
707
11%
2170
4%
707
28%
707
14%
1634
November1st to 15thNight
22%
730
13%
2453
6%
730
31%
730
12%
1809
November16th to endNight
21%
750
9%
2520
3%
750
28%
750
9%
1991
December1st to 15thNight
12%
750
7%
2595
1%
750
19%
750
6%
2138
December16th to endNight
12%
800
7%
2880
1%
800
19%
800
6%
2395

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

Occurrence of each ForecastData
Points
Cloud CoverDay
18%8%36%5%3445%7%33%
45572
Night
19%9%36%5%3445%6%29%
45310
TransparencyDay
50%6%14%19%8%
45246
Night
54%5%11%18%8%
45154
SeeingDay
23%8%27%25%12%3
6254
Night
23%10%29%26%9%1
14208

By Month

Percentage Cloud Cover NE (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
14%14%5%8%8%36%6%45%21%
1253
16th to endDay
14%9%36%6%36%5%48%29%
1555
February1st to 15thDay
11%11%47%6%45%5%6%7%30%
1575
16th to endDay
15%13%5%6%6%35%336%30%
1422
March1st to 15thDay
16%8%35%6%2435%7%35%
1923
16th to endDay
14%9%46%425%446%37%
1936
April1st to 15thDay
18%7%25%425%45%7%36%
2007
16th to endDay
24%6%25%323346%37%
2145
May1st to 15thDay
19%8%36%5%25%346%34%
2261
16th to endDay
23%7%35%43335%6%33%
2443
June1st to 15thDay
25%7%35%424446%31%
2475
16th to endDay
25%7%2443445%7%30%
2475
July1st to 15thDay
13%5%245%345%6%9%37%
2475
16th to endDay
17%6%245%345%6%8%34%
2548
August1st to 15thDay
18%414425%45%7%38%
2152
16th to endDay
12%5%25%5%3446%8%41%
2256
September1st to 15thDay
18%6%25%434347%39%
1977
16th to endDay
17%5%24313347%48%
1790
October1st to 15thDay
17%6%25%5%2445%7%36%
1650
16th to endDay
25%8%25%5%2335%6%30%
1701
November1st to 15thDay
24%8%36%43445%5%28%
1405
16th to endDay
16%13%5%10%6%35%35%6%22%
1440
December1st to 15thDay
23%12%49%8%45%436%17%
1364
16th to endDay
21%11%6%12%7%45%45%6%16%
1344
January1st to 15thNight
17%11%48%9%46%5%46%20%
2685
16th to endNight
15%10%36%6%47%46%7%27%
2667
February1st to 15thNight
12%13%36%5%46%446%31%
2285
16th to endNight
17%12%47%5%345%4428%
2051
March1st to 15thNight
17%7%36%7%345%5%6%31%
1986
16th to endNight
16%10%5%6%42334436%
1936
April1st to 15thNight
22%7%36%5%3445%6%30%
1608
16th to endNight
23%7%35%322346%37%
1485
May1st to 15thNight
20%8%37%5%25%35%5%33%
1361
16th to endNight
22%6%35%4345%48%30%
1325
June1st to 15thNight
26%9%35%42345%7%26%
1155
16th to endNight
24%6%36%6%25%446%28%
1155
July1st to 15thNight
15%425%446%5%5%9%36%
1155
16th to endNight
18%6%345%35%6%7%7%30%
1298
August1st to 15thNight
18%5%25%5%345%5%8%34%
1477
16th to endNight
13%6%25%5%4435%8%38%
1593
September1st to 15thNight
17%6%25%423445%42%
1650
16th to endNight
16%413323445%48%
1840
October1st to 15thNight
18%5%25%5%34446%38%
1980
16th to endNight
26%10%25%5%2345%6%27%
2170
November1st to 15thNight
23%9%36%6%33346%29%
2453
16th to endNight
20%11%5%9%6%34446%22%
2520
December1st to 15thNight
21%13%5%9%7%36%45%6%16%
2595
16th to endNight
23%13%6%8%8%45%445%15%
2880

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
62%8%10%11%7%
1254
16th to endDay
50%7%12%20%8%
1555
February1st to 15thDay
50%6%15%20%5%1
1578
16th to endDay
56%5%8%20%8%
1422
March1st to 15thDay
49%5%12%20%10%2
1934
16th to endDay
47%410%23%11%1
1936
April1st to 15thDay
47%5%10%20%13%2
2007
16th to endDay
49%310%18%15%3
2145
May1st to 15thDay
51%410%20%12%
2261
16th to endDay
51%6%14%18%9%
2447
June1st to 15thDay
53%413%17%9%
2475
16th to endDay
52%7%14%17%7%
2475
July1st to 15thDay
40%7%19%23%8%
2316
16th to endDay
46%7%18%20%6%
2376
August1st to 15thDay
42%8%18%23%6%
2138
16th to endDay
38%7%22%25%5%
2256
September1st to 15thDay
44%5%15%22%11%
1977
16th to endDay
37%415%29%12%
1790
October1st to 15thDay
46%5%17%21%8%
1650
16th to endDay
53%5%12%19%7%
1701
November1st to 15thDay
56%7%14%13%7%
1405
16th to endDay
64%5%12%13%3
1440
December1st to 15thDay
68%6%12%7%4
1364
16th to endDay
69%6%10%11%3
1344
January1st to 15thNight
63%7%10%12%5%
2685
16th to endNight
52%7%11%19%8%
2667
February1st to 15thNight
51%5%13%18%8%1
2286
16th to endNight
58%5%9%16%9%1
2051
March1st to 15thNight
53%5%8%18%12%1
1998
16th to endNight
50%39%20%13%1
1936
April1st to 15thNight
53%48%19%11%2
1608
16th to endNight
48%49%15%18%3
1485
May1st to 15thNight
52%5%9%22%9%1
1361
16th to endNight
51%6%12%21%7%
1327
June1st to 15thNight
57%5%11%14%9%1
1155
16th to endNight
56%6%14%14%7%
1155
July1st to 15thNight
42%7%14%27%8%
1085
16th to endNight
49%8%16%19%6%
1208
August1st to 15thNight
47%7%16%21%6%
1466
16th to endNight
42%7%18%24%6%
1593
September1st to 15thNight
44%5%11%28%9%
1650
16th to endNight
36%5%15%27%13%1
1840
October1st to 15thNight
46%5%14%24%8%1
1980
16th to endNight
57%410%19%6%
2170
November1st to 15thNight
57%413%16%6%
2453
16th to endNight
62%7%12%13%2
2520
December1st to 15thNight
69%5%9%12%2
2595
16th to endNight
70%6%8%11%3
2880

Seeing (when cloud cover <= 80%)
Color Meanings:
Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
21%16%40%10%11%
60
16th to endDay
15%8%36%28%9%1
163
February1st to 15thDay
18%10%31%28%9%1
236
16th to endDay
23%14%24%23%12%1
212
March1st to 15thDay
19%13%32%25%7%2
264
16th to endDay
20%11%33%19%10%4
224
April1st to 15thDay
25%14%29%18%10%2
210
16th to endDay
24%11%27%20%10%5%
210
May1st to 15thDay
24%7%27%22%13%4
352
16th to endDay
29%6%26%25%10%2
439
June1st to 15thDay
33%422%27%10%1
420
16th to endDay
29%424%25%14%3
420
July1st to 15thDay
19%325%30%16%4
400
16th to endDay
21%219%33%16%5%
444
August1st to 15thDay
17%120%33%21%5%
260
16th to endDay
13%7%23%32%18%4
268
September1st to 15thDay
21%7%27%29%12%1
255
16th to endDay
17%11%28%28%9%4
249
October1st to 15thDay
18%16%26%19%14%4
225
16th to endDay
28%18%29%15%5%1
240
November1st to 15thDay
28%13%29%18%8%1
235
16th to endDay
23%12%32%23%6%1
240
December1st to 15thDay
32%11%32%16%6%
164
16th to endDay
23%28%37%9%1
64
January1st to 15thNight
22%14%35%21%4
750
16th to endNight
20%13%36%23%5%
781
February1st to 15thNight
20%9%36%25%7%
704
16th to endNight
24%11%25%25%10%1
631
March1st to 15thNight
20%9%34%26%7%
716
16th to endNight
22%13%30%24%8%1
704
April1st to 15thNight
27%8%26%26%9%
503
16th to endNight
26%7%27%24%12%1
495
May1st to 15thNight
23%5%23%29%14%3
495
16th to endNight
21%5%33%26%12%1
472
June1st to 15thNight
33%317%33%11%1
330
16th to endNight
25%318%35%15%1
330
July1st to 15thNight
16%220%37%19%3
310
16th to endNight
17%424%33%17%2
419
August1st to 15thNight
18%219%36%21%2
494
16th to endNight
16%419%40%17%1
525
September1st to 15thNight
19%8%27%32%11%1
495
16th to endNight
18%7%32%30%11%
657
October1st to 15thNight
20%8%33%26%10%1
660
16th to endNight
30%12%29%20%6%
707
November1st to 15thNight
27%14%28%20%7%1
730
16th to endNight
26%14%28%22%7%1
750
December1st to 15thNight
29%17%32%17%3
750
16th to endNight
31%14%30%16%6%1
800
Page generated at 2017-03-15 12:32:35. Version ac04

Copyright 2017 A. Danko


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